initial commit (#2)

Adding the actual code

.env.sample

@@ -0,0 +1,9 @@
+# Environment Config
+
+SLACK_SIGNING_SECRET=
+SLACK_BOT_TOKEN=
+twitter_consumer_key=
+twitter_consumer_secret=
+twitter_access_token_key=
+twitter_access_token_secret=
+

.gitignore

@@ -0,0 +1,3 @@
+node_modules
+.DS_Store
+.env

README.md

@@ -1,2 +1,61 @@
-# tiktok-slackbot
-Watch TikToks in Slack
+# TikTok to Twitter Slackbot
+
+Wish you could watch TikToks in Slack? Me too. I made a Slackbot fix that by uploading TikToks to Twitter and then posting the Tweets back in a Slack thread.  
+
+---
+ 1~ Slackbot replies to post:
+<kbd>
+  <img src="media/reply.gif">
+</kbd>
+
+<details>
+  <summary>2~ You watch TikTok</summary>
+
+  <kbd>
+    <img src="media/thread.gif">
+  </kbd>
+</details>
+
+## Features  
+* Works with short and long TikTok urls
+* Can handle many concurrent requests
+* Unfurls links posted in threads
+
+## How it works  
+
+I hoped to use the [unfurl api](https://api.slack.com/docs/message-link-unfurling) to attach the video. Unforunately, that's not possible and Slack only shows [previews](https://slack.com/help/articles/204399343-Share-links-and-set-preview-preferences) from whitelisted apps. The good news is that Twitter is whitelisted. So we can upload a video to Twitter and then let Slack unfurl that.
+
+![Software Flow Diagram Here](media/flow.svg)
+
+
+I decided not to upload the MP4 directly to Slack because that would hog your Slack storage and litter the files search.
+
+### General Flow:  
+Slack -> TikTok -> Twitter -> Slack
+
+1. Recieve a `link_shared` [event](https://api.slack.com/events/link_shared) from Slack for a TikTok
+2. Download the MP4 from TikTok
+3. Tweet the MP4
+4. Reply to original Slack message with Tweet
+
+
+## Setup 
+
+`cp .env.sample .env` to make the `.env` file.
+
+1. Create a [Twitter developer account](https://developer.twitter.com/en/apply-for-access) and put the credentials to the `.env` file.
+2. Create a Slackbot (follow instructions in src/slackbot.js) and put the credentials in the `.env` file.  
+3. Run `npm start` 
+4. Add your server address to the **Event Subscriptions** page in Slack. ex: `https://example.com/slack/events`  
+    * Your bot must be running before you can add the URL
+    * You can use ngrok for local testing
+    * See [Bolt docs](https://api.slack.com/tutorials/hello-world-bolt) for help setting up a Slackbot.
+5. Add the Slackbot to any channel you want it to respond in.
+
+### Hosting  
+
+I recommend hosting for free on [glitch.com](https://glitch.com/). However, Google App Engine or even a Lambda function should work as well.
+
+## Contributing
+
+Feel free to open a PR or create an issue if you'd like to improve the project!